Overview
Egg freezing (oocyte cryopreservation) lets someone store their own eggs for possible use later. The first half of the process is the same as IVF: hormone injections encourage several eggs to mature, and the eggs are collected in a short procedure under sedation. Instead of being fertilised, the mature eggs are frozen and stored in liquid nitrogen. If they are used later, they are thawed, fertilised by ICSI and any resulting embryo is transferred to the womb.
People freeze eggs for medical reasons, such as before cancer treatment or ovarian surgery that may damage fertility, and for personal reasons, such as not yet having a partner or not being ready for a child. ESHRE's guideline on female fertility preservation covers both. Most clinics now freeze eggs by vitrification, a very fast freezing method that the HFEA says is more successful than the older slow-cooling technique.
Egg freezing is not a guarantee of a future baby. The American Society for Reproductive Medicine estimates that each frozen egg has roughly a 2 to 12 per cent chance of leading to a baby, falling with age at freezing, and says planned egg freezing is most likely to succeed when eggs are frozen before 38. How many eggs to aim for, and whether more than one cycle is worthwhile, are questions for a fertility specialist.
Who it's for
- People about to have chemotherapy, radiotherapy or surgery that may affect the ovaries.
- People with conditions linked to early loss of eggs, such as endometriosis affecting the ovaries or a family history of early menopause, depending on a specialist's assessment.
- People who want to keep the option of using their own eggs later because they are not ready, or do not have a partner, now.
- People having IVF who cannot use fresh eggs on the day, for example if sperm cannot be obtained.
Whether a treatment suits you depends on your own history and tests — discuss it with a fertility specialist.
Step by step
Consultation and tests
A specialist reviews your history and orders tests of ovarian reserve (such as an AMH blood test and an ultrasound count of small follicles), along with infection screening. The results help estimate how many eggs might be collected.
Ovarian stimulation
Daily hormone injections, usually self-administered, run for about ten to twelve days. Several monitoring scans and blood tests check how the follicles are growing and guide the dose.
Trigger injection
When the follicles are ready, a final injection completes egg maturation. Egg collection is timed for about a day and a half later.
Egg collection
Under sedation or anaesthesia, a fine needle guided by a vaginal ultrasound probe draws eggs from the follicles. It usually takes around 20 to 30 minutes, and most people go home the same day.
Freezing
In the laboratory, mature eggs are identified, treated with a protective solution and frozen by vitrification. The clinic should tell you how many eggs were collected and how many were mature enough to freeze.
Storage
Frozen eggs are kept in liquid nitrogen tanks. Storage is usually charged each year, and you will sign a consent and storage agreement that sets out how long eggs can be kept and what happens at the end.
Using the eggs later
When you decide to use them, eggs are thawed, and those that survive are fertilised by ICSI. Embryos are cultured for a few days and one is transferred to the womb in a prepared cycle.
Typical timeline
- Consultation and ovarian reserve tests
- Usually 1–4 weeks before starting
- Ovarian stimulation
- About 10–12 days
- Trigger to egg collection
- About 36 hours
- Recovery
- Usually back to normal activity within a day or two; bloating may last until the next period
- Whole cycle
- About 2–3 weeks from the first injection; some people need more than one cycle
- Storage
- Years, under the clinic's storage agreement and local law
What it costs
The cost comes in three parts: the freezing cycle, yearly storage, and the later IVF cycle to use the eggs. Published Thai prices we found include Superior A.R.T.'s ELITE package at 185,000 baht (standard price 259,000) with three years' storage; Bangkok Hospital's two-part package for fly-in patients at an estimated 264,500 baht plus 1,300 baht per vial per year for storage; and Beyond IVF from 100,000 baht, with storage at 2,000 baht per egg per year. Storage may be charged per egg, per vial or per batch, so compare the yearly cost for the number of eggs you expect to freeze.
Risks and side effects
- Ovarian hyperstimulation syndrome (OHSS): an over-response to the injections that causes swollen ovaries, bloating and pain. It is usually mild, but rare severe cases need hospital care.
- Egg collection complications: bleeding, infection or injury to nearby organs are uncommon but possible.
- Fewer eggs than hoped: people with a low ovarian reserve may produce few eggs, and collection is not always possible.
- Not all eggs survive thawing, fertilise or develop into embryos, and frozen eggs do not guarantee a pregnancy.
- A false sense of security: ASRM notes that relying on frozen eggs may lead some people to delay trying for a pregnancy, which can lower their overall chance.
- Pregnancy at an older age, when the eggs are eventually used, carries higher risks for both the pregnant person and the baby.
Questions to ask a clinic
- Based on my age and test results, how many eggs might you expect to collect in one cycle?
- How many eggs would you suggest I aim to store, and might I need more than one cycle?
- Do you freeze eggs by vitrification, and what proportion of your patients' eggs survive thawing?
- What does the package include, and how much storage is covered?
- Is storage charged per egg, per vial or per batch, and can the fee rise?
- Am I eligible to freeze eggs here, and on what conditions could I use them later in Thailand?
- What would it cost to thaw and fertilise the eggs and transfer an embryo?
- Can eggs be moved to a clinic in another country, and who arranges it?
Frequently asked questions
What is the best age to freeze eggs?
ASRM says egg freezing tends to work best in the 20s to early 30s and is most likely to succeed before 38. The right time for you depends on your ovarian reserve and plans, so discuss it with a fertility specialist.
How many eggs are collected in one cycle?
It varies widely. The HFEA says most patients under 38 have around 7 to 14 eggs collected, and that collection may not be possible for people with a low ovarian reserve.
How long can eggs stay frozen?
That depends on the law and the clinic's storage agreement. In the UK, eggs can be stored for up to 55 years with consent renewed every 10 years; Thai clinics set their own terms, so ask for them in writing before you start.
Is egg freezing painful?
The injections can sting and cause bloating. Egg collection is done under sedation or anaesthesia, and cramping for a day or two afterwards is common.
Will frozen eggs give me a baby later?
Not necessarily. Each frozen egg has a modest chance of leading to a baby, and that chance falls with age at freezing. Frozen eggs keep an option open; they are not a guarantee.
Can I freeze eggs if I am single?
Some Thai clinics state that they accept single women for egg freezing, and others refer to using eggs with a legal spouse's sperm. Ask each clinic in writing whether you can freeze eggs and, separately, whether you could later use them in Thailand.










